Light cycles in Tron
If we had to give up all of the other movie-based gadgets so that only one could be made, it would be the light cycles in Tron. It's incredible that this film was made in 1982 -- watching this clip now still gets our blood rushing.
Where the hell is it?
Fully immersive gaming environments don't exist in the Tron sense, but software and hardware is getting very close to being able to offer it.
I want one now!
If you took Second Life, tweaked Johnny Chung Lee's head-tracking technology and got yourself a vibrating gaming chair you could just about get all Tron-ed up. If wearing headgear isn't your thing though, Alienware's massive curved display will have you thinking you're inside the game without a funny pair of glasses in sight.